Gas line installation cost

Running a gas line costs $15 to $40 a linear foot, typically around $25, with most household jobs landing between $300 and $1,200. A short run from an existing line to a new range is at the bottom. A new line to a fire pit at the end of the yard, with a permit and a pressure test, is at the top.

This is one of the few plumbing jobs where doing it yourself is a genuinely bad idea regardless of how handy you are.

What it costs

Why the tankless line is its own row

The most common reason a household needs new gas pipe is a tankless water heater.

A tank heater draws perhaps 40,000 BTU an hour. A whole-house tankless draws 150,000 to 199,000. The existing 1/2 inch line that fed the tank cannot deliver that, and neither can a meter sized for the old load.

So the quote for a tankless conversion often contains a $500 to $2,000 gas line and sometimes a utility meter upgrade on top. That is not a contractor padding the estimate; it is physics, and it is the single most common surprise in tankless pricing.

Sizing, and why it is not just about the appliance

Gas pipe is sized for the total demand of everything downstream of it and the distance the gas has to travel. Adding one appliance to a line that already runs a furnace, a water heater and a range can undersize the whole branch, and the symptom is not a failure. It is a burner that yellows, a furnace that short cycles, and a water heater that cannot keep up when the range is on.

A proper installer does a load calculation. Ask to see it if the job is anything more than a short run to a single appliance.

What a legitimate installation includes

• A permit, and an inspection
• The correct material for the location: black iron indoors, coated steel or approved polyethylene underground, and CSST only where it is permitted and bonded
• A shut-off valve at the appliance, within reach
• A sediment trap at each appliance
• A pressure test held for the required period, witnessed by the inspector
• Bonding, where CSST is used, which is a lightning safety requirement and gets missed

The permit is not optional paperwork here. An unpermitted gas line is a problem when you sell the house and a much bigger one if there is ever a fire and an insurer looks at how it was installed.

Frequently asked questions

Can I run gas pipe myself?

In most jurisdictions a homeowner may do work on their own residence, and in most jurisdictions it still needs a permit and an inspection. Whether you should is a different question. A water leak is a mess; a gas leak is an explosion, and the failure mode is not one you get to learn from.

How do I know if I smell gas?

Leave the house first. Do not touch light switches, do not use a phone inside, do not open the garage door with the opener. Ring the gas utility from outside; they attend free and usually fast. Only after they clear it is it a plumber's job.

Is flexible CSST as good as black iron?

It is approved, it installs faster, and it costs less in labor. It must be bonded to the electrical grounding system, because it is thin-walled and lightning has caused failures where bonding was skipped. Ask specifically whether the bonding was done and whether the inspector checked it.

Can I convert an appliance from propane to natural gas?

Most ranges, furnaces and water heaters take a conversion kit for $50 to $200 plus labor, because the orifices and the regulator differ. Some cannot be converted at all. Check the model before you assume.

Do I need a permit for a grill line?

Almost always yes, and it is the one people skip most. It is also the one running under a patio where nobody will ever see it again, which is exactly why the inspection exists.